The present disclosure generally fixation devices for cranial bones, and in particular to dynamic decompressive craniotomy fixation devices and related methods.
Increased intracranial pressure can follow traumatic brain injuries, strokes, tumors or other injuries, ailments or the like. When increased intracranial pressure presents an obstacle to simple maneuvers, such as head elevation, sedation, or osmotic diuretics (mannitol), then consideration should be given towards performing a decompressive craniotomy or craniectomy for example. Other factors, issues, preferences or considerations may also lead to the need or desire to perform a decompressive craniotomy or craniectomy. This potentially lifesaving procedure is being performed at an increased rate.
Decompressive craniotomy or craniectomy is a neurosurgical procedure used to alleviate elevated intracranial pressure due to brain swelling. Typically, a portion of the cranium over the affected area of the patient's brain is removed and at least a portion of the dura of the brain is thereby fenestrated to accommodate the swollen portion of the brain and reduce the intracranial pressure. Once the bone portion(s) is/are removed, the compromised cranium is left “open” for a period of time ranging from a few weeks to potentially several months to allow a sufficient amount of swelling to dissipate. During that time, there typically is a change in the cerebral spinal fluid (CSF) dynamics of the patient, which can result in hydrocephalus or CSF leakage for example. CSF leakage, in particular, may increase infection risk.
Replacement of the removed portion(s) of the cranium or skull plate after decompressive craniotomy or craniectomy as soon as medically safe, possible or advantageous is often desirable, such as in consideration of the alteration of the CSF dynamics as discussed above, risk of brain injury due to the compromised cranium, and cosmesis purposes. Once brain swelling is resolved, the removed bone portion(s) or flap(s), or a replacement thereof, is typically fixed to the skull to close the skull via another procedure to surgery.
Decompressive hinge craniotomy or craniectomy, where the portions(s) of bone or the bone plate is not removed, is gaining more acceptance as a safer alternative to the temporary complete removal of bone or a cone plate during a typical decompressive craniotomy or craniectomy. Decompressive hinge craniotomy or craniectomy may reduce the risks associated with complete removal of bone for an extend period of time, as discussed above.
Decompressive hinge craniotomy or craniectomy typically involves removing or disconnecting a section of cranial bone or bone plate over or about the affected area of a patient's brain, and then attaching or coupling the removed or disconnected bone with a device or mechanism at least generally into its original position. The device(s) or mechanism(s) may allow the removed or disconnected bone or bone plate to shift in one direction with respect to the skull. For example, the device(s) or mechanism(s) may allow the removed or disconnected bone or bone plate to translate in an outward direction away from the brain as the brain swells to reduce the intracranial pressure.
Once the brain swelling is resolved, the device(s) or mechanism(s) used to attach or couple the disconnected or removed bone plate to the skull and dynamically allow for brain swelling should ideally allow the bone plate to return to its original position for permanent fixation without the requirement of further surgery. Considering the state of the art that exists today, there is a need for better devices and methods for cranial fixation that would allow optimal, dynamic immediate treatment of increased intracranial pressure, and obviate the need for a fixation reoperation after the increased intracranial pressure subsides.